Quote remaining shell variables

Author: Copilot

action.yml

@@ -53,13 +53,13 @@ runs:
       if [[ ! -z "${url}" ]]; then
         echo "Installing crane for ${os} on ${arch}"
         tmp=$(mktemp -d)
-        cd ${tmp}
+        cd "${tmp}"
         fname="go-containerregistry_${os}_${arch}.tar.gz"
         curl -o "$fname" -fsSL --retry 5 --retry-delay 1 --retry-all-errors "${url}/${fname}"
         tar xzf "$fname" "${out}"
         chmod +x "${tmp}/${out}"
-        PATH=${PATH}:${tmp}
-        echo "${tmp}" >> $GITHUB_PATH
+        PATH="${PATH}:${tmp}"
+        echo "${tmp}" >> "$GITHUB_PATH"
       fi
 
       # NB: username doesn't seem to matter.